The present invention relates generally to microphones which are used remotely from a receiving/broadcasting unit, such as a hand-held microphone. Such microphones are most widely used in association with transceivers commonly known as Citizen Band Radios and are ordinarily small and light enough to be hand held.
In previous remote microphone units selection of the receiving or broadcasting channel of the transceiver required manipulation of controls located on the main chassis of the transceiver. The microphones were attached to the chassis of the transceiver by a flexible means, such as a cable. Such microphones, however, had no facility associated with the microphone unit for controlling the operation of the microphone. Manipulation of a channel selection control located on the main chassis of the transceiver was required by the operator of the unit to vary the receiving or broadcasting channel of the transceiver which would also display the selected channel.
In the instance of a person driving a car or truck, any time spent on the visual inspection and physical manipulation of controls presents severe dangers since a vehicle travelling at the maximum permitted rate of speed of 55 m.p.h. will travel 80 feet in only one second. Thus, even a fraction of a second of inattention to the road could result in an accident.
Previously available microphones have had control means associated with the hand-held unit as well as digital display of the selected channel. In addition the microphone unit has had controls for switching the transceiver from a receiving to a transmitting mode of operation as well as means for switching the transceiver on and off. All such operations require the visual attention and manipulation thereby contributing to the dangers inherent while operating a vehicle. United States Patents to Coenen, et al. U.S. Pat. No. 3,822,372 and Guttinger U.S. Pat. No. 3,586,807 discloses remote microphones which have controls associated with the microphone unit.
In the present invention the microphone unit, which is remote from the chassis of the transceiver unit, has a means associated with the remote microphone unit for displaying, by improved means, in digital form, the channel of the transceiver. In such a manner, the microphone unit can be held in view of the driver to rapidly select a desired channel. The conventional push-to-talk and on/off switches associated with the prior art remote microphones may also be included in the microphone housing. Various lighting means may be incorporated with the channel display, to permit viewing and operation of the microphone in dark locations.
Also, means for selecting the desired channel must be such as to reduce, as much as possible, the time required. Even though the microphone unit has the channel display on it, repeatedly having to look at the channel display to see if the proper channel has been obtained can contribute to a dangerous condition.
In the present invention, means for switching the channel is achieved by solid state circuitry, which may be included in the microphone case, for rapidly, easily and accurately obtaining the proper channel.